This has happened far too many times for it to be an rare occurrence. I think people on this forum forgive these things because they are afraid to upset the vendor and will not get a free updated tune. The free tune is a thing of the past so forget that, forgiving the vendor only reinforces the idea that they can get away with it. They would be mighty upset if this happened to them on the purchase of something not for their car or any other supplier of parts for their car.
People pay good money and are not treated fairly.

Purchasing this pulley means you have to get the scatter shield from a vendor who treats his customers with respect. A membership in AAA or CAA is also recommended, even with a shield. Who knows how far from home you'll be when it grenades.
These parts were replaced free at first when they failed, now you get a small discount on another one and you pay for any damage done to your car. As I said years back they will all fail at some point, even the OEM ones will fail but nowhere near as soon.